A New Overwatch Update Tweaks Mercy And Removes Four Maps From Deathmatch

Earlier this week, Blizzard rolled out a big Overwatch update that brought major changes to Mercy and D.Va, as well as the new Junkertown escort map that was revealed last month. Now a smaller patch is out that makes some tweaks to Mercy's on-fire meter, and removes four maps from the Deathmatch and Team Deathmatch rotations.
The Mercy update changed her ultimate ability from Resurrect to Valkyrie, which enhances all of her abilities for 20 seconds and reduces her Resurrect cooldown to ten seconds. That change was apparently causing some issues, as the patch "adjusts" (although precisely how isn't made clear) its contribution to Mercy's on-fire meter.  
As for the maps—Hanamura, Horizon Lunar Colony, Temple of Anubis, and Volskaya Industries—Blizzard didn't say why they were removed, but they will remain available for custom matches.
The update is live now in the PC version of Overwatch, and will be "rolled into a larger patch for PlayStation 4 and Xbox One at a later date." The full patch notes are below.
GENERAL UPDATES
General

• The credit that Mercy’s Resurrect contributes toward her on-fire meter has been adjusted to account for the recent changes in its functionality

Arcade Updates

• Hanamura, Horizon Lunar Colony, Temple of Anubis, or Volskaya Industries have been removed from the Deathmatch and Team Deathmatch map rotation, but can still be selected in Custom Games

User Interface Updates

• Made several adjustments to the spectator camera to improve the viewing experience

BUG FIXES
General

• Fixed a bug that caused the audio from Junkertown’s front gate to play when previewing and opening Loot Boxes
• Fixed a bug that prevented the stagger and knockdown VO from canceling active voice lines
• Fixed a bug that allowed an incorrect voice line to play when firing D.Va's Micro Missiles
• Fixed an issue that caused the spectator camera to lose track of heroes and player-controlled objects (e.g. Junkrat’s Rip-Tire)

Heroes

• Fixed a bug that prevented Genji and Mercy's ultimate voice lines from functioning properly when the Oni or Winged Victory skins were equipped

Maps

• Fixed an issue that caused sound effects to continuously repeat when using a beam weapon (e.g. Zarya's Particle Cannon) to destroy the motorcycle in the attackers' spawn room on Junkertown
• Fixed an issue that activated audio cues that are typically associated with enemy hits when shooting the motorcycle on Junkertown